[Sync] Replacing NULL with nullptr in code and null in comments for components/sync/

components/sync/engine_impl/sync_encryption_handler_impl_unittest.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/sync/engine_impl/sync_encryption_handler_impl.h"
 
 #include <stdint.h>
 
 #include <memory>
 
@@ skipping 637 matching lines @@
 
   // Ensure the bootstrap is encoded properly (a base64 encoded encrypted blob
   // of list values containing the keystore keys).
   std::string decoded_bootstrap;
   ASSERT_TRUE(base::Base64Decode(keystore_bootstrap, &decoded_bootstrap));
   std::string decrypted_bootstrap;
   ASSERT_TRUE(GetCryptographer()->encryptor()->DecryptString(
       decoded_bootstrap, &decrypted_bootstrap));
   JSONStringValueDeserializer json(decrypted_bootstrap);
   std::unique_ptr<base::Value> deserialized_keystore_keys(
-      json.Deserialize(NULL, NULL));
+      json.Deserialize(nullptr, nullptr));
   ASSERT_TRUE(deserialized_keystore_keys.get());
-  base::ListValue* keystore_list = NULL;
+  base::ListValue* keystore_list = nullptr;
   deserialized_keystore_keys->GetAsList(&keystore_list);
   ASSERT_TRUE(keystore_list);
   ASSERT_EQ(2U, keystore_list->GetSize());
   std::string test_string;
   keystore_list->GetString(0, &test_string);
   ASSERT_EQ(old_keystore_key, test_string);
   keystore_list->GetString(1, &test_string);
   ASSERT_EQ(kKeystoreKey, test_string);
 
   // Now make sure a new encryption handler can correctly parse the bootstrap
@@ skipping 1626 matching lines @@
   EXPECT_CALL(*observer(),
               OnBootstrapTokenUpdated(_, KEYSTORE_BOOTSTRAP_TOKEN));
   {
     ReadTransaction trans(FROM_HERE, user_share());
     encryption_handler()->SetKeystoreKeys(
         BuildEncryptionKeyProto(kRawKeystoreKey), trans.GetWrappedTrans());
   }
 }
 
 }  // namespace syncer